<?php //$Id: select.php,v 1.2.2.2 2007/12/11 13:01:13 nfreear Exp $

require_once($CFG->dirroot.'/user/filters/lib.php');

/**
 * Generic filter based on a list of values.
 */
class user_filter_select extends user_filter_type {
	/**
	 * options for the list values
	 */
	var $_options;

	var $_field;

	var $_default;

	/**
	 * Constructor
	 * @param string $name the name of the filter instance
	 * @param string $label the label of the filter instance
	 * @param boolean $advanced advanced form element flag
	 * @param string $field user table filed name
	 * @param array $options select options
	 * @param mixed $default option
	 */
	function user_filter_select($name, $label, $advanced, $field, $options, $default=null) {
		parent::user_filter_type($name, $label, $advanced);
		$this->_field   = $field;
		$this->_options = $options;
		$this->_default = $default;
	}

	/**
	 * Returns an array of comparison operators
	 * @return array of comparison operators
	 */
	function get_operators() {
		return array(0 => get_string('isanyvalue','filters'),
					 1 => get_string('isequalto','filters'),
					 2 => get_string('isnotequalto','filters'));
	}

	/**
	 * Adds controls specific to this filter in the form.
	 * @param object $mform a MoodleForm object to setup
	 */
	function setupForm(&$mform) {
		$objs = array();
		$objs[] =& $mform->createElement('select', $this->_name.'_op', null, $this->get_operators());
		$objs[] =& $mform->createElement('select', $this->_name, null, $this->_options);
		$grp =& $mform->addElement('group', $this->_name.'_grp', $this->_label, $objs, '', false);
		$grp->setHelpButton(array('select', $this->_label, 'filters'));
		$mform->disabledIf($this->_name, $this->_name.'_op', 'eq', 0);
		if (!is_null($this->_default)) {
			$mform->setDefault($this->_name, $this->_default);
		}
		if ($this->_advanced) {
			$mform->setAdvanced($this->_name.'_grp');
		}
	}

	/**
	 * Retrieves data from the form data
	 * @param object $formdata data submited with the form
	 * @return mixed array filter data or false when filter not set
	 */
	function check_data($formdata) {
		$field	= $this->_name;
		$operator = $field.'_op';

		if (array_key_exists($field, $formdata) and !empty($formdata->$operator)) {
			return array('operator' => (int)$formdata->$operator,
						 'value'	=> (string)$formdata->$field);
		}

		return false;
	}

	/**
	 * Returns the condition to be used with SQL where
	 * @param array $data filter settings
	 * @return string the filtering condition or null if the filter is disabled
	 */
	function get_sql_filter($data) {
		$operator = $data['operator'];
		$value	= addslashes($data['value']);
		$field	= $this->_field;

		switch($operator) {
			case 1: // equal to
				$res = "='$value'"; break;
			case 2: // not equal to
				$res = "<>'$value'"; break;
			default:
				return '';
		}
		return $field.$res;
	}

	/**
	 * Returns a human friendly description of the filter used as label.
	 * @param array $data filter settings
	 * @return string active filter label
	 */
	function get_label($data) {
		$operators = $this->get_operators();
		$operator  = $data['operator'];
		$value	 = $data['value'];

		if (empty($operator)) {
			return '';
		}

		$a = new object();
		$a->label	= $this->_label;
		$a->value	= '"'.s($this->_options[$value]).'"';
		$a->operator = $operators[$operator];

		return get_string('selectlabel', 'filters', $a);
	}
}

